Head gimbal assembly and storage device provided with the same

ABSTRACT

A head gimbal assembly includes a load beam, a wiring member including a metal plate disposed on the load beam, a magnetic head attached to a tip section of the wiring member, and a piezoelectric element that is fixed to and supported by supporting pads and deforms in response to a voltage applied thereto. The metal plate includes a tip section to which the magnetic head is fixed, and a base section that is spaced apart from the tip section and is fixed to the load beam. The supporting pads include first and second supporting pads proximate to the tip section and distal from the base section and a third supporting pad proximate to the base section and distal to the tip section, each of supporting pads separated from and independent of both the tip section and the base section.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of co-pending U.S.application Ser. No. 14/190,740, which was filed on Feb. 26, 2014, andwhich is based upon and claims the benefit of priority from JapanesePatent Application No. 2013-236673, filed Nov. 15, 2013, the entirecontents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to ahead gimbal assemblyused in a storage device and a disk unit provided with the same.

BACKGROUND

In recent years, disk drives such as a magnetic disk drives and anoptical disk drives are widely used as an external recording device andan image recording device of a computer.

The magnetic disk drive generally includes a magnetic disk placed in acase, a spindle motor that supports and rotates the magnetic disk, and ahead gimbal assembly (HGA). The head gimbal assembly includes asuspension that is attached to a tip section of an arm, a flexure (awiring member) that is provided on the suspension and is connected tothe outside, and a magnetic head that is supported on the suspensionwith a gimbal section of the flexure. A wiring of the flexure iselectrically connected to the magnetic head. Moreover, the suspensionincludes a load beam and a base plate fixed to a base end side of theload beam, and the base plate is fixed to the tip section of the arm.

In recent years, an HGA in which a thin-film piezoelectric element (PZTelement) is mounted on a gimbal section of a flexure and a microscopicdisplacement is caused in a seek direction of a magnetic head by anexpansion and contraction of the piezoelectric element, has beenproposed. With this HGA, the operation of the magnetic head may becontrolled by varying a voltage applied to the piezoelectric element.

However, in the above-described HGA, when the piezoelectric elementexpands or contracts by a voltage application, the piezoelectric elementbends in a thickness direction thereof and an out-of-plane vibration issometimes generated. The out-of-plane vibration is transferred to a loadbeam via the flexure, unnecessarily exciting the resonance frequency ofthe load beam. As a result, the positioning accuracy of the magnetichead is reduced.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a hard disk drive (HDD) accordingto a first embodiment.

FIG. 2 is a perspective view showing a head gimbal assembly of the HDD.

FIG. 3 is a perspective view showing a tip section and a gimbal sectionof the head gimbal assembly.

FIG. 4 is an exploded perspective view showing a magnetic head,piezoelectric elements, a flexure (a wiring member) , and a load beam ofthe head gimbal assembly.

FIG. 5 is a sectional view of the tip section of the head gimbalassembly taken on the line A-A of FIG. 3.

FIG. 6 is a sectional view of the head gimbal assembly corresponding toFIG. 5 in a state in which the piezoelectric element expands.

FIG. 7 is a plan view schematically showing a drive state of themagnetic head by the piezoelectric elements.

FIG. 8 is an exploded perspective view showing a magnetic head,piezoelectric elements, a flexure, and a load beam of a head gimbalassembly according to a second embodiment.

FIG. 9 is an exploded perspective view showing a magnetic head,piezoelectric elements, a flexure, and a load beam of a head gimbalassembly according to a third embodiment.

FIG. 10 is a diagram showing a comparison among the vibrations generatedin the cross-track direction in a light gap position of the magnetichead in the head gimbal assemblies according to the first to thirdembodiments and a head gimbal assembly according to a comparativeexample.

DETAILED DESCRIPTION

An exemplary embodiment provides a head gimbal assembly and a disk unitthat may suppress the vibration of a load beam.

In general, according to one embodiment, a head gimbal assembly includesa load beam, a wiring member including a metal plate disposed on theload beam, an insulating layer disposed on the metal plate and the loadbeam, and a conductive layer forming first and second wirings, amagnetic head electrically connected to the first wiring of the wiringmember and attached to a tip section of the metal plate, and apiezoelectric element that is fixed to and supported by supporting padsand configured to deform in response to a voltage applied theretothrough the second wiring. The metal plate includes a tip section towhich the magnetic head is fixed, and a base section that is spacedapart from the tip section and is fixed to the load beam. The supportingpads include first and second supporting pads proximate to the tipsection and distal from the base section and a third supporting padproximate to the base section and distal to the tip section, each of thesupporting pads separated from and independent of both the tip sectionand the base section.

Hereinafter, with reference to the drawings, a hard disk drive (HDD)will be described in detail as a magnetic disk unit according to anembodiment.

First Embodiment

FIG. 1 shows an internal structure of the HDD from which a top cover isremoved. As shown in FIG. 1, the HDD includes a housing 10. The housing10 includes a base 12 in the shape of a rectangular box, with an openingon a top face thereof, and a top cover (not shown) that closes the topopening of the base 12 by being secured to the base 12 with a pluralityof screws. The base 12 includes a rectangular bottom wall 12 a and aside wall 12 b erected along the outer edge of the bottom wall.

In the housing 10, two magnetic disks 16 are provided as recording mediaand a spindle motor 18 is provided as a drive section that supports androtates the magnetic disks. The spindle motor 18 is provided on thebottom wall 12 a. Each magnetic disk 16 is formed to have a diameter of2.5 inches (6.35 cm), for example, and includes a magnetic recordinglayer on a top face and a lower face. The magnetic disks 16 areconcentrically fitted onto a hub (not shown) of the spindle motor 18 andare clamped by a clamp spring 27 and thereby fixed to the hub. As aresult, the magnetic disks 16 are supported in a state in which themagnetic disks 16 are parallel to the bottom wall 12 a of the base 12.The magnetic disks 16 are rotated by the spindle motor 18 at apredetermined speed.

In the housing 10, a plurality of magnetic heads 17 that record andreproduce information on and from the magnetic disks 16 and a head stackassembly (hereinafter referred to as an HSA) 22 that movably supportsthe magnetic heads 17 with respect to the magnetic disks 16 areprovided. Moreover, in the housing 10, a voice coil motor (hereinafterreferred to as a VCM) 24 that rotationally moves and positions the HSA22, a ramp loading mechanism 25 that holds the magnetic heads in anunloading position which is away from the magnetic disks when themagnetic heads 17 move to the outermost periphery of the magnetic disks16, a latch mechanism 26 that holds the HSA in a retraction positionwhen an impact or the like is given to the HDD, and a substrate unit 21including a connector and so forth, are provided.

On the outer surface of the bottom wall 12 a of the base 12, a printedcircuit board (not shown) is secured with screws. The printed circuitboard controls the operations of the spindle motor 18, the VCM 24, andthe magnetic heads 17 via the substrate unit 21. Near the side wall 12 bof the base 12, a circulating filter 23 that captures dust generated inthe housing due to the operation of the movable section is provided andis located on the outside of the magnetic disks 16. Moreover, near theside wall 12 b of the base 12, a breathing filter 15 that captures dustfrom the air flowing into the housing 10 is provided.

As shown in FIG. 1, the HSA 22 includes a rotatable bearing unit 28,four arms 32 that are attached to the bearing unit in a stackedconfiguration, a head gimbal assembly (hereinafter referred to as anHGA) 30 extending from each arm 32, and spacer rings (not shown)disposed in such a way as to be stacked between the arms 32. Each arm 32is formed to have a long flat plate-like shape from stainless steel,aluminum, or the like, for example. Each arm 32 includes a tip sectionon the side where an extension end is located, and, in this tip section,a caulking bearing surface provided with a caulking hole (not shown) isformed. The bearing unit 28 includes a pivot erected in the bottom wall12 a of the base 12 near the outer periphery of the magnetic disks 16and a cylindrical sleeve rotatably supported on the pivot with a bearingplaced between the cylindrical sleeve and the pivot.

FIG. 2 is a perspective view showing the HGA 30. As shown in FIGS. 1 and2, each HGA 30 includes a suspension 34 extending from the arm 32 and amagnetic head 17 supported on the extension end of the suspension 34.

The suspension 34 includes a rectangular base plate 42 made of a metalplate which is several hundreds of micrometers in thickness and a loadbeam 35 in the shape of a long leaf spring, the load beam 35 being madeof a metal plate which is several tens of micrometers in thickness. Abase end of the load beam 35 is disposed in such a way as to be stackedon a tip section of the base plate 42 and is fixed to the base plate 42by performing welding in multiple places. The width of the base end ofthe load beam 35 is formed to be substantially equal to the width of thebase plate 42. At the tip of the load beam 35, a long rod-like tab 46 isprovided in such a way as to protrude therefrom.

The base plate 42 is provided with a circular opening and a ring-shapedprotrusion 43 located around this opening in a base end thereof. Thebase plate 42 is secured to the tip section of the arm 32 as a result ofthe protrusion 43 being fitted into the circular caulking hole (notshown) formed in the caulking bearing surface of the arm 32 and theprotrusion 43 being crimped.

The HGA 30 includes a pair of piezoelectric elements (PZT elements) 50and a long strip-shaped flexure (wiring member) 40 for transmitting arecording and reproduction signal and a drive signal of thepiezoelectric element. As shown in FIG. 2, a tip-side portion 40 a ofthe flexure 40 is mounted on the load beam 35 and the base plate 42, anda rear portion (an extending section) 40 b extends from a side edge ofthe base plate 42 to the outside and extends along a side edge of thearm 32. In addition, a connection end of the flexure 40 located at thetip of the extending section 40 b is connected to a main FPC 21 b whichwill be described later.

A tip section of the flexure 40 located on a tip section of the loadbeam 35 forms a gimbal section 36, and the magnetic head 17 and thepiezoelectric elements 50 are mounted on the gimbal section 36. Themagnetic head 17 includes a slider having a virtually prismatic shapeand a recording element and a reproduction element which are provided inthe slider, and is fixed on the gimbal section 36 and is supported onthe load beam 35 with the gimbal section 36 placed between the magnetichead 17 and the load beam 35. A pair of the piezoelectric elements (PZTelements) 50 is attached to the gimbal section 36 and is located, nearthe magnetic head 17, on the side of the load beam 35 where the base endthereof is located.

FIG. 3 is a perspective view showing an enlarged magnetic head portionof the HGA 30, FIG. 4 is an exploded perspective view showing themagnetic head, the piezoelectric elements, the flexure, and the loadbeam of the HGA, and FIG. 5 is a sectional view of the HGA, showing aportion in which the piezoelectric element is mounted.

As shown in FIGS. 2 to 5, the flexure 40 includes a metal thin plate (abacking layer) 44 a made of stainless steel or the like, the metal thinplate (the backing layer) 44 a serving as a base, an insulating layer 44b formed on the metal thin plate, a conductive layer (a wiring pattern)44 c that is formed on the insulating layer 44 b and forms a pluralityof wiring 45 a, and a protective insulating layer (not shown) coveringthe conductive layer 44 c, and is formed as a long, strip-shapedlaminated plate. The side of the tip-side portion 40 a of the flexure 40where the metal thin plate 44 a is located is pasted or spot-welded tothe surfaces of the load beam 35 and the base plate 42.

In the gimbal section 36 of the flexure 40, the metal thin plate 44 aincludes a rectangular tongue section 36 a located on the tip side, arectangular base end 36 b located on the base end side with a spacing(distance) between the tongue section 36 a and the base end 36 b, and apair of right and left link sections 36 c extending from the tonguesection 36 a to the base end 36 b. In the space between the tonguesection 36 a and the base end 36 b, a pair of island-shaped firstsupporting sections (supporting pads) 36 d and a pair of island-shapedsecond supporting sections (supporting pads) 36 e are provided. Thesefirst and second supporting sections 36 d and 36 e are formed of a metalthin plate.

The pair of first supporting sections 36 d is located near the tonguesection 36 a and is disposed side by side in the width direction of thegimbal section 36. Moreover, the pair of second supporting sections 36 eis located near the base end 36 b and is disposed side by side in thewidth direction of the gimbal section 36. Between each second supportingsection 36 e and the base end 36 b, a slit section or a notch section 38is provided, and the second supporting sections 36 e and the base end 36b are separated from each other. The first supporting sections 36 d andthe second supporting sections 36 e are arranged in the longitudinaldirection of the gimbal section 36 with a space section between thefirst supporting sections 36 d and the second supporting sections 36 e.

In the gimbal section 36, the insulating layer 44 b and the conductivelayer 44 c extend to the tip side of the tongue section 36 a passingover the base end 36 b, passing through the slit section or the notchsection 38, passing over the pair of second supporting sections 36 e,passing through the space section, and passing over the pair of firstsupporting sections 36 d.

The magnetic head 17 is fixed to the tongue section 36 a with anadhesive and the insulating layer 44 b is disposed between the magnetichead 17 and the tongue section 36 a. The base end 36 b of the metal thinplate 44 a is fixed to the load beam 35 by welding or the like. Aportion of the tongue section 36 a which is substantially at the centerthereof makes contact with a dimple (a support protrusion) 48 providedin the tip section of the load beam 35 in such a way as to protrudetherefrom. The tongue section 36 a and the magnetic head 17 may swing orroll about the dimple 48 by elastic deformation of the link sections 36c.

The piezoelectric elements 50 are formed to have a long, rectangularplate-like shape and expand and contract in the longitudinal directionthereof. The piezoelectric elements 50 are fixed to the insulating layer44 b of the gimbal section 36 with an adhesive or the like. Thepiezoelectric elements 50 are disposed in such a way that thelongitudinal direction thereof is parallel to the longitudinal directionof the load beam 35 and the flexure 40. As a result, the twopiezoelectric elements 50 are disposed in such a way that thepiezoelectric elements 50 are arranged parallel to each other and aspace is left therebetween in the width direction of the gimbal section36.

As shown in FIG. 5, one end of each piezoelectric element 50 in thelongitudinal direction thereof, that is, an end of the piezoelectricelement 50 on the side where the magnetic head 17 is located issupported on the first supporting section 36 d. The other end of eachpiezoelectric element 50 in the longitudinal direction thereof, that is,an end of the piezoelectric element 50 on the side where the base end 36b is located is supported on the second supporting section 36 e.

As shown in FIGS. 3 to 5, some of the wiring 45 a of the flexure 40 arewiring for transmitting a recording and reproduction signal to themagnetic head 17, and these wiring extend to the magnetic head 17 andinclude electrode pads 45 b at the extension ends thereof. Theseelectrode pads 45 b and the recording and reproduction elements of themagnetic head 17 are electrically joined to each other with solder or anelectrically-conducting adhesive such as a silver paste. Moreover, someof the wiring 45 a of the flexure 40 transmit a drive signal to thepiezoelectric elements 50, and these wiring extend to the vicinity ofthe piezoelectric elements 50 and include electrode pads 45 c at theextension ends thereof. These electrode pads 45 c and the piezoelectricelements 50 are electrically joined to each other with solder or anelectrically-conducting adhesive such as a silver paste. Incidentally,these wiring 45 a extend to the connection end side of the flexure alongthe flexure 40 and are connected to connection pads (not shown) providedat the connection end.

Each piezoelectric element 50 expands and contracts in the longitudinaldirection of the flexure 40 by a voltage application as indicated witharrows in FIGS. 6 and 7. By driving these two piezoelectric elements 50in such a way that the piezoelectric elements 50 expand and contact inopposite directions, the tongue section 36 a of the gimbal section 36may be swung via the flexure 40 and the magnetic head 17 may bedisplaced in a seek direction. In this embodiment, since the spacebetween the first supporting section 36 d and the second supportingsection 36 e that support the piezoelectric elements 50 and the base end36 b of the metal thin plate 44 a is mainly maintained by the lowrigidity of the insulating layer 44 b, the out-of-plane vibration duringdriving of the piezoelectric elements is prevented from beingtransferred to the load beam 35 via the base end 36 b of the metal thinplate 44 a.

As shown in FIG. 1, the HSA 22 includes a supporting frame extendingfrom the bearing unit 28 in a direction opposite to the arm 32, and avoice coil forming part of the VCM 24 is embedded in the supportingframe. When the HSA 22 configured as described above is mounted on thebase 12, a lower end of the pivot of the bearing unit 28 is fixed to thebase 12, and the bearing unit 28 is erected in such a way as to besubstantially parallel to the spindle of the spindle motor 18. Eachmagnetic disk 16 is located between the two HGAs 30. During operation ofthe HDD, the magnetic heads 17 attached to the suspensions 34 face thetop face and the lower face of each magnetic disk 16 and are located onthe sides where the faces of the magnetic disk 16 are located. The voicecoil fixed to the supporting frame is located between a pair of yokes 37fixed on the base 12, and these yokes and a magnet (not shown) fixed toone yoke form the VCM 24.

As further shown in FIG. 1, the substrate unit 21 includes a main body21 a formed of a flexible printed circuit board, and the main body 21 ais fixed to the bottom wall 12 a of the base 12. On the main body 21 a,a connector and an electronic component for connection with the printedcircuit board (both not shown) are mounted.

The substrate unit 21 includes a main flexible printed circuit board(hereinafter referred to as a main FPC) 21 b extending from the mainbody 21 a. An extension end of the main FPC 21 b forms a connection endand is fixed to the vicinity of the bearing unit 28 of the HSA 22. Theflexure 40 of each HGA 30 is mechanically and electrically connected tothe connection end of the main FPC 21 b. As a result, the substrate unit21 is electrically connected to the magnetic head 17 and thepiezoelectric elements 50 via the main FPC 21 b and the flexure 40.

As shown in FIG. 1, the ramp loading mechanism 25 includes a ramp 47disposed outside the magnetic disks 16 on the bottom wall 12 a of thebase 12 and the tab 46 (see FIGS. 2 to 4) extending from the tip of eachsuspension 34. When the HSA 22 rotationally moves about the bearing unit28 and the magnetic heads 17 move to the retraction position locatedoutside the magnetic disks 16, each tab 46 engages a ramp surface formedin the ramp 47 and is then pulled up by the inclination of the rampsurface. As a result, the magnetic heads 17 are unloaded from themagnetic disks 16 and are held in the retraction position.

According to the HDD and the HGA 30 configured as described above, thepiezoelectric elements 50 are attached to the gimbal section 36 of theflexure 40, and, by applying a voltage to the piezoelectric elements 50via the flexure 40, the magnetic head 17 attached to the gimbal sectionmay be displaced in a seek direction. As a result, by controlling thevoltage applied to the piezoelectric elements 50, the position of themagnetic head 17 may be finely controlled and the positioning accuracyof the magnetic head may be improved.

Moreover, in the gimbal section 36 to which the piezoelectric elements50 are attached, the first supporting sections 36 d and the secondsupporting sections 36 e of the metal thin plate 44 a, the firstsupporting sections 36 d and the second supporting sections 36 esupporting both ends of the piezoelectric elements 50 in thelongitudinal direction thereof, are separated from and independent ofthe base end 36 b of the metal thin plate 44 a. The first supportingsections 36 d and the second supporting sections 36 e and the base end36 b of the metal thin plate 44 a are connected to one another mainly bythe insulating layer 44 b having low rigidity. Therefore, even when anout-of-plane vibration is generated in the piezoelectric elements 50 andthe first and second supporting sections 36 d and 36 e during driving ofthe piezoelectric elements 50, the out-of-plane vibration are preventedfrom being transferred to the load beam 35 via the base end 36 b of themetal thin plate 44 a. As a result, a head gimbal assembly thatsuppresses unnecessary resonance excitation of the load beam 35 andimproves the positioning accuracy of the magnetic head 17 may beobtained.

Next, HGAs according to other embodiments will be described. In theother embodiments described below, portions that are identical to thoseof the first embodiment described above are identified with the samereference characters, and the detailed descriptions thereof are omitted.

Second Embodiment

FIG. 8 is an exploded perspective view showing a magnetic head 17,piezoelectric elements 50, a flexure 40, and a load beam 35 of an HGA 30according to a second embodiment. According to this embodiment, in agimbal section 36, part of each of a pair of second supporting sections36 e of a backing metal thin plate 44 a is connected to the base end 36b by a long bridge section 41 . The width of the bridge section 41 isformed to be sufficiently smaller than the width of the secondsupporting section 36 e. Except for the bridge section 41, each secondsupporting section 36 e is separated from the base end 36 b by the notchsection 38.

In the second embodiment, the other structures of the HGA 30 and the HDDare the same as the structures of the HGA 30 and the HDD of the firstembodiment described previously.

Also in the second embodiment structured as described above, anout-of-plane vibration that is transferred from the second supportingsection 36 e to the base end 36 b of the metal thin plate 44 a may bereduced and unnecessary resonance excitation of the load beam may besuppressed. Moreover, since the bridge section 41 is provided, thesupporting stability of the piezoelectric elements 50 is improved. As aresult, a head gimbal assembly that improves the positioning accuracy ofthe magnetic head 17 may be obtained.

Third Embodiment

FIG. 9 is an exploded perspective view showing a magnetic head 17,piezoelectric elements 50, a flexure 40, and a load beam 35 of an HGA 30according to a third embodiment. According to this embodiment, in agimbal section 36, the second supporting section 36 e of a backing metalthin plate 44 a is formed as one common second supporting section. Thesecond supporting section 36 e is formed to have a rectangular shape andextends in the width direction of the gimbal section 36. Moreover, thesecond supporting section 36 e is separated from a base end 36 b by theslit section or the notch section 38. The single second supportingsection 36 e supports one end of each of the two piezoelectric elements50.

In the third embodiment, the other structures of the HGA 30 and the HDDare the same as the structures of the HGA 30 and the HDD of the firstembodiment described previously.

Also in the third embodiment structured as described above, anout-of-plane vibration that is transferred from the second supportingsection 36 e to the base end 36 b of the metal thin plate 44 a may bereduced and unnecessary resonance excitation of the load beam may besuppressed. As a result, a head gimbal assembly and the HDD thatimproves the positioning accuracy of the magnetic head 17 may beobtained. In a modification of the third embodiment, the secondsupporting section 36 e may be connected to the base end 36 b by one ora plurality of bridge sections.

FIG. 10 shows the results of a simulation of frequency transmissioncharacteristics of cross-track direction displacement at a write gapposition (or read-write element position) of a magnetic head for a drivevoltage of the piezoelectric elements 50. The simulation is performedusing a finite-element analysis on the HGAs according to the first tothird embodiments described above and a comparative example. Moreover,in FIG. 10, the frequency transmission characteristics in the 7 kHz bandwhich is a primary torsional resonance frequency of the load beam areshown. In an HGA according to the comparative example, a secondsupporting section is integrally formed in abase end of a metal thinplate.

The load beam 35 used in the simulation is a stainless plate which is 30μm in thickness. In the flexure 40, the backing metal thin plate is astainless plate which is 18 μm in thickness, the insulating layer 44 bis 8 μm in thickness, and the conductive layer 44 c is 12 μm inthickness. The thickness of each piezoelectric element 50 is 10 μm.Moreover, the conditions of a voltage application to the piezoelectricelements 50 are the same.

It is found from FIG. 10 that, under the same condition of a voltageapplication, the primary torsional resonance gains of the load beams inthe first to third embodiments are smaller than the primary torsionalresonance gain of the load beam in the comparative example. Therefore,in simulations, the first to third embodiments described above are shownto prevent the out-of-plane vibration of the piezoelectric elements 50that is generated during driving when the torsional resonance of theload beam is unnecessarily excited and thereby enhance the positioningperformance of the suspension and the magnetic head.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

In the embodiments described above, as the arms of the HSA, plate-likearms which are independent of one another are used, but the arms are notlimited to such arms; a structural member into which a plurality ofso-called E-block-shaped arms and a bearing sleeve are integratedtogether may be applied. The magnetic disk is not limited to a 2.5-inchmagnetic disk, and a magnetic disk of other size may be used. The numberof magnetic disks is not limited to two, and one or three or moremagnetic disks may be used. The number of HGAs may also be increased orreduced in accordance with the number of placed magnetic disks.

What is claimed is:
 1. A head gimbal assembly comprising: a load beam; awiring member including a metal plate and an insulating layer disposedon the metal plate and the load beam, the metal plate including a tipsection that is movable away from the load beam and a base section thatis fixed to the load beam; a magnetic head electrically connected to afirst wiring of the wiring member and attached to a tip section of thewiring member; and an expanding and contracting element that is fixed tosupporting pads through the insulating layer and configured to deform inresponse to a voltage applied thereto through a second wiring of thewiring member, the supporting pads including first and second supportingpads proximate to the tip section of the metal plate and distal from thebase section and third and fourth supporting pads proximate to the basesection and distal from the tip section of the metal plate, the firstand second supporting pads being structurally separated from andindependent of both the tip section of the metal plate and the basesection, and the third and fourth supporting pads being structurallyconnected to the base section.
 2. The head gimbal assembly of claim 1,wherein the expanding and contracting element includes a first elementfixed to the first and third supporting pads and a second element fixedto the second and fourth supporting pads.
 3. The head gimbal assembly ofclaim 1, wherein the third and fourth supporting pads are structurallyconnected to the base section by respective bridge sections, each havinga width that is substantially smaller than a width of the respectivethird and fourth supporting pads.
 4. The head gimbal assembly of claim1, wherein the expanding and contracting element includes first andsecond strips each having a longitudinal axis aligned parallel to and oneither side of a longitudinal axis of the metal plate.
 5. The headgimbal assembly of claim 4, wherein the first and second strips deformin response to the voltage applied thereto to rotate the magnetic headabout an axis that is perpendicular to a plane of the metal plate.
 6. Astorage device comprising: a disk-shaped recording medium; a drivingmotor that supports and rotates the recording medium; and a head gimbalassembly including: a load beam, a wiring member including a metal plateand an insulating layer disposed on the metal plate and the load beam,the metal plate including a tip section that is movable away from theload beam and a base section that is fixed to the load beam, a magnetichead electrically connected to a first wiring of the wiring member andattached to a tip section of the wiring member, and an expanding andcontracting element that is fixed to supporting pads through theinsulating layer and configured to deform in response to a voltageapplied thereto through a second wiring of the wiring member, thesupporting pads including first and second supporting pads proximate tothe tip section of the metal plate and distal from the base section andthird and fourth supporting pads proximate to the base section anddistal from the tip section of the metal plate, the first and secondsupporting pads being structurally separated from and independent ofboth the tip section of the metal plate and the base section, and thethird and fourth supporting pads being structurally connected to thebase section.
 7. The device of claim 6, wherein the expanding andcontracting element includes a first element fixed to the first andthird supporting pads and a second element fixed to the second andfourth supporting pads.
 8. The device of claim 6, wherein the third andfourth supporting pads are structurally connected to the base section byrespective bridge sections, each having a width that is substantiallysmaller than a width of the respective third and fourth supporting pads.9. The device of claim 6, wherein the expanding and contracting elementincludes first and second strips each having a longitudinal axis alignedparallel to and on either side of a longitudinal axis of the metalplate.
 10. The device of claim 9, wherein the first and second stripsdeform in response to the voltage applied thereto to rotate the magnetichead about an axis that is perpendicular to a plane of the metal plate.